Originally called Cope after Jesse Cope’s gold discoveries in April 1869 are what led to what was referred to as the “Cope Boom.” The Cope Mining District was formed on May 22, and by June, 300 people had populated the area. On July 31, the name was officially changed to Mountain City. By end of summer, the population had ballooned to 700. The town had twenty saloons, a dozen hotels, six restaurants, and two breweries. By the end of 1870 the town had more than 200 buildings, and a population of 1,000. There were also six lawyers and three doctors that had established practice in the town.

In January of 1872 the mines showed signs of slowing down. In 1872 the mines earned only 33,000 and the population shrunk to only sixty-seven by 1875. During these lean years many homesteaders came into the area and a large ranching industry, which survives today, developed.

In 1932, the great copper discovery at Rio Tinto, once again saw a rise in growth and new businesses in Mountain City. When the Rio Tinto boom died out in the late 1940's, Mountain City slowly shrank.

During the 1950's the discovery of uranium on nearby Granite Ridge stirred up some excitement in Mountain City. But despite all the interest, very little uranium ore was ever shipped.